code: def test_forward(self):
      neck = FPEM_FFM(
          in_channels=self.in_channels, conv_out=self.conv_out
      )
      neck.init_weights()
      out = neck(self.features)
      self.assertTrue(out[0].shape == torch.Size([1, 8, 64, 64]))
      self.assertTrue(out[1].shape == out[0].shape)
      self.assertTrue(out[2].shape == out[0].shape)
      self.assertTrue(out[3].shape == out[0].shape)
  
file_path: mmocr/tests/test_models/test_textdet/test_necks/test_fpem_ffm.py
imports: import unittest
  import torch
  from mmocr.models.textdet.necks.fpem_ffm import FPEM, FPEM_FFM
label_desc: Use image node_id 2 for calling the TestFPEM_FFM obj's underlying member method code with example usage: obj.test_forward() without return types